This invention relates to a connector in which a front holder is attached to a housing, thereby preventing the withdrawal of metal terminals provided within the housing.
FIGS. 15 to 17 show a first related connector of this kind disclosed in JP-A-9-251874. As shown in FIGS. 15 to 17, this connector 50 includes a plurality of metal terminals (not shown) connected respectively to end portions of wires, a housing 52 for receiving the plurality of metal terminals therein, and a front holder 53 attached to the housing 52.
The housing 52 has many terminal receiving chambers 54 formed therein, and the metal terminals are received in these terminal receiving chambers 54, respectively. An elastic retaining arm portion (not shown) is provided in a projected manner in each terminal receiving chamber 54, and is supported at one end thereof on an upper face of the terminal receiving chamber 54. The metal terminal is retained by this elastic retaining arm portion. Slide grooves 55 are formed in opposite (right and left) side faces of the housing 52, respectively, and the pair of slide grooves 55 are exposed to the exterior. A housing-side first retaining portion 56 and a housing-side second retaining portion 57 are provided in each slide groove 55 in a projected manner.
The front holder 53 can be inserted into the housing 52 from a mating connector-fitting side of this housing, and a plurality of arm deformation prevention portions 60 are formed at an insertion end thereof. A pair of elastically deformable operating plates 59 are formed at opposite (right and left) sides of the front holder 53. A holder-side first retaining portion 61 and a holder-side second retaining portion 62 (which can be displaced by elastic deformation of the operating plate 59) are formed on each operating plate 59.
Next, an assembling operation of the connector 50 will be described. The front holder 53 is inserted into the housing 52 from the fitting side thereof. This front holder is inserted into a provisionally-retaining position where the pair of right and left holder-side first retaining portions 61 of the front holder 53 are retained respectively by the pair of right and left housing-side first retaining portions 56 of the housing 52 as shown in FIG. 16. In this provisionally-retained condition, the metal terminals (not shown) are inserted respectively into the terminal receiving chambers 54 of the housing 52 through rear open ends thereof, and the metal terminals are retained by the elastically-deformed elastic retaining arm portions (not shown), respectively.
Then, the operator moves the pair of operating plates 59 of the front holder 53 in an inserting direction A, thereby forcibly inserting the front holder 53. The front holder 53 is inserted into a completely-retaining position where the pair of right and left holder-side second retaining portions 62 of the front holder 53 are retained respectively by the pair of right and left housing-side second retaining portions 57 of the housing 52 as shown in FIG. 17. As a result, each arm deformation prevention portion 60 is inserted in a flexure space between the corresponding elastic retaining arm portion (not shown) and the upper face of the corresponding terminal receiving chamber 54, thereby limiting the elastic deformation of the elastic retaining arm portion (not shown). As a result, each metal terminal (not shown) is prevented form withdrawal.
When the front holder 53 is located in the provisionally-retaining position, the movement of the front holder 53 in the inserting direction A Is prevented by the retaining engagement of the pair of right and left second retaining portions 57 with the pair of right and left second retaining portions 62. Also, the movement of the front holder 53 in a withdrawing direction B is prevented by the retaining engagement of the pair of right and left first retaining portions 56 with the pair of right and left first retaining portions 61, as shown in FIG. 16. Therefore, the front holder 53 is provisionally attached to the housing 52, and the arm deformation prevention portions 60 of the front holder 53 are held in such a position as not to prevent the insertion of the metal terminals. When the front holder 53 is located in the completely-retaining position, the movement of the front holder 53 in the withdrawing direction B is prevented by the retaining engagement of the pair of right and left second retaining portions 57 with the pair of right and left second retaining portions 62 as shown in FIG. 17, and therefore the front holder 53 is completely attached to the housing 52, and the arm deformation prevention portions 60 of the front holder 53 are held respectively in predetermined positions to prevent the withdrawal of the metal terminals.
When the front holder 63 is moved from the completely-retaining position to the provisionally-retaining position because of some trouble (for example, because part of the plurality of metal terminals have failed to be properly inserted), the pair of operating plates 59 of the front holder 53 are pressed away from each other as indicated by arrows D (FIG. 15), thereby canceling the locking engagement of the pair of right and left holder-side second retaining projections 62 with the pair of housing-side second retaining projections 57, and then the front holder 53 is moved in the withdrawing direction B. The front holder 53 is drawn into the position where the pair of right and left holder-side first retaining projections 61 of the front holder 53 are retainingly engaged respectively with the pair of right and left first housing-side retaining projections 56 as shown in FIG. 16. At this time, the forcible displacement of the pair of right and left operating plates 59 of the front holder 53 is canceled, so that the front holder is held in this provisionally-retained position.
The above connector 50 has advantages that the insertion of the metal terminals can be effected while the front holder 53 is kept provisionally attached to the housing 52 and that when there is an error in the metal terminal-inserting operation, a metal terminal-reinserting operation can be effected.
In the related connector 50, however, when the front holder 53 is to be returned from the completely-retaining position to the provisionally-retaining position, the pair of right and left operating plates 59 must be operated at the same time, and therefore the operator can not easily effect this operation in a one-touch manner, which has invited a problem that the operability is bad. Particularly in the case of a flattened thin-type connector with a large width, the distance between the pair of right and left operating plates 59 is so large that the operator can not operate the pair of right and left operating plates 59 unless he uses both hands, and therefore the operability is not user friendliness.
Also, FIGS. 18 to 20 show a second related connector of this kind disclosed in JP-A-7-57809. As shown in FIGS. 18 to 20, this connector 150 includes a plurality of metal terminus 151 (shown in FIG. 20) connected respectively to end portions of wires, a housing 152 for receiving the plurality of metal terminals 151 therein, and a front holder 153 attached to the housing 152.
The housing 152 has many terminal receiving chambers 154 formed therein, and the metal terminals 151 are received in these terminal receiving chambers 154, respectively. An elastic retaining arm portion 155 is provided in a projected manner in each terminal receiving chamber 154, and is supported at one end thereof on an upper face of the terminal receiving chamber 154. The metal terminal 151 is retained by this elastic retaining arm portion 155. A housing-side first retaining portion 156 and a housing-side second retaining portion 157 are formed on and project from a front wall of the terminal receiving chamber 154.
The front holder 153 can be inserted into the housing 152 from a mating connector-fitting side of this housing, and a plurality of arm deformation prevention portions 160 are formed at an insertion end thereof. Holder-side first retaining portions 161 and holder-side second retaining portions 162 (which can be displaced by elastic deformation) are formed on the front holder 153 in a projected manner.
Next, an assembling operation of the connector 150 will be described. The front holder 153 is inserted into the housing 152 from the fitting side thereof. This front holder is inserted into a provisionally-retaining position where the holder-side first retaining portions 161 of the front holder 153 are retained respectively by the housing-side first retaining portions 156 of the housing 152 as shown in FIG. 19. In this provisionally-retained condition, the metal terminals 151 are inserted respectively into the terminal receiving chambers 154 of the housing 152 through rear open ends thereof, and the metal terminals 151 are retained by the elastically-deformed elastic retaining arm portions 155, respectively.
Then, the front holder 153, provisionally retained in the housing 152, is further inserted into the housing 152. More specifically, the front holder is inserted into a completely-retaining position where the holder-side second retaining portions 162 of the front holder 153 are retained respectively by the housing-side second retaining portions 157 of the housing 152 as shown in FIG. 20. As a result, each arm deformation prevention portion 160 is inserted in a flexure space between the corresponding elastic retaining arm portion 155 and the upper face of the corresponding terminal receiving chamber 154, thereby limiting the elastic deformation of the elastic retaining arm portion 155. As a result, each metal terminal 151 is prevented form withdrawal.
When the front holder 153 is located in the provisionally-retaining position, the movement of the front holder 153 in an inserting direction A is prevented by the retaining engagement between the second retaining portions 157 and 162, and the movement of the front holder 153 in a withdrawing direction B is prevented by the retaining engagement between the first retaining portions 156 and 161, as shown in FIG. 19. Therefore, the front holder 153 is provisionally attached to the housing 152, and the arm deformation prevention portions 160 of the front holder 153 are held in such a position as not to prevent the insertion of the metal terminals 151. When the front holder 153 is located in the completely-retaining position, the movement of the front holder 153 in the withdrawing direction B is prevented by the retaining engagement between the second retaining portions 157 and 162 as shown in FIG. 20, and therefore the front holder 153 is completely attached to the housing 152, and the arm deformation prevention portions 160 of the front holder 153 are held respectively in predetermined positions to prevent the withdrawal of the metal terminals 151.
The above connector 150 has an advantage that the insertion of the metal terminals 151 can be effected while the front holder 153 is kept provisionally attached to the housing 152
In the second related connector 150, however, the housing-side first retaining portions 156 and housing-side second retaining portions 157 of the housing 152 project from the front walls of the terminal receiving chambers 154, and when viewed from the direction of insertion of the front holder 153 into the housing 152, these first and second retaining portions 156 and 157 are disposed within a terminal receiving area where the plurality of terminal receiving chambers 154 are provided. Therefore, there are limitations such as a requirement that the housing-side first and second retaining portions 156 and 157 and the holder-side first and second retaining portions 161 and 162 should be so provided as not to affect the insertion of terminals of the mating connector. Therefore, these retaining portions can not be provided in a small-size connector in which small metal terminals are used, and the distance between adjacent terminal receiving chambers is small, and each terminal receiving chamber is formed by a small space. Even if such retaining portions can be provided, the desired position-holding force can not be obtained. Thus, these problems have been encountered.